The 3D effect should beat any other camera driven 3D system seen, since it mimicks the eyes movements when viewing something close or far away. So, all in all, the depth should be greater, and should allow for a flip easier between viewing pararell distance objects (and make them appear with more depth), and cross eye closer objects.
It isn't that much here... but £15 probably isn't that far off actually.
It is a 2 hour 40 minute film though, and the IMAX experience in 3D will blow away the cinema varient.